Need some help here.

My Livorsi GPS speedo crapped out the end of last season. From all indications it's the battery.

I've been reading several threads on this subject and need some guidance.

I've read (with some technical skills) you can change the battery yourself.

I've also read you can connect to your current gps (in my case a Garmin 182). Are there any advantages / disadvantages to connecting to an existing gps? Will the recall still work? Lastly, is there a particular cable (name and part #) that I need to make this work?

Thanks in advance for any help or ideas.